\begin{table}[htbp]\centering
\def\sym#1{\ifmmode^{#1}\else\(^{#1}\)\fi}
\caption{Leaks \label{leaks}}
\begin{tabular}{l*{5}{c}}
\hline\hline
                &\multicolumn{1}{c}{(1)}&\multicolumn{1}{c}{(2)}&\multicolumn{1}{c}{(3)}&\multicolumn{1}{c}{(4)}&\multicolumn{1}{c}{(5)}\\
                &\multicolumn{1}{c}{sum\_leaks\_EUonly}&\multicolumn{1}{c}{sum\_leaks\_EUonly}&\multicolumn{1}{c}{sum\_leaks\_EUonly}&\multicolumn{1}{c}{EU-Attributed Leaks (residuals)}&\multicolumn{1}{c}{EU-Attributed Leaks (working residuals)}\\
                &     b/se         &     b/se         &     b/se         &     b/se         &     b/se         \\
\hline
main            &                  &                  &                  &                  &                  \\
Mean Right-Left &    -0.23\sym{**} &    -0.24\sym{***}&    -0.47\sym{***}&                  &                  \\
                &   (0.11)         &   (0.09)         &   (0.14)         &                  &                  \\
Mean R-L Political Polarization&                  &     0.13\sym{***}&    -0.14         &                  &                  \\
                &                  &   (0.05)         &   (0.13)         &                  &                  \\
B-spline on [1976m4,2015m12)&                  &                  &   133.42\sym{***}&                  &                  \\
                &                  &                  &  (38.11)         &                  &                  \\
B-spline on [1986m3,2025m11)&                  &                  &    25.69\sym{***}&                  &                  \\
                &                  &                  &   (7.65)         &                  &                  \\
B-spline on [1996m2,2035m10)&                  &                  &    63.95\sym{***}&                  &                  \\
                &                  &                  &  (15.49)         &                  &                  \\
B-spline on [2006m1,2045m9)&                  &                  &     0.00         &                  &                  \\
                &                  &                  &      (.)         &                  &                  \\
Mean Right-Left (residuals)&                  &                  &                  &    -0.06\sym{**} &    -0.34\sym{*}  \\
                &                  &                  &                  &   (0.02)         &   (0.18)         \\
Mean R-L Political Polarization (residuals)&                  &                  &                  &     0.03\sym{***}&     0.15\sym{**} \\
                &                  &                  &                  &   (0.01)         &   (0.05)         \\
Constant        &    -2.04\sym{***}&    -7.73\sym{***}&   -43.57\sym{***}&     0.01         &     0.17         \\
                &   (0.41)         &   (1.99)         &  (11.58)         &   (0.04)         &   (0.27)         \\
\hline
N               &      117         &      117         &      117         &      117         &      117         \\
R-squared       &                  &                  &                  &     0.04         &     0.03         \\
\hline\hline
\multicolumn{6}{l}{\footnotesize \sym{*} \(p<0.10\), \sym{**} \(p<0.05\), \sym{***} \(p<0.01\)}\\
\end{tabular}
\end{table}
